A work towards creation of ecological network started more than 30 years ago being linked, first of all, with necessity of more balanced ecosystems of landscapes heavy transformed for agriculture (Munteanu, Ganea, Ostaficiuc, Andreev, 1987). It was based on general ecosystem principles (Munteanu, Andreev, 1990) and included the notions of core areas (“bio-cenosis oases” in that version) and biological corridors (Fauna …, 1990). National Biodiversity Strategy and Action Plan (NBSAP, 2001) has introduced a legal basis for activities devoted to ecological network development.